يبدو حارس المرمى جاهزا.

يبدو means seems or appears here.

It is the present-tense form of بدا. More specifically, it is third-person masculine singular, because the subject is حارس المرمى (the goalkeeper), which is grammatically masculine singular.

So the basic pattern is:

• يبدو + noun + state/description
• seems + noun + adjective/state

Because verb-first word order is very common in Modern Standard Arabic.

So:

• يبدو حارس المرمى جاهزًا = neutral, very natural in MSA
• حارس المرمى يبدو جاهزًا = also possible, but it puts more focus on the goalkeeper

Arabic often allows both orders, but verb + subject is especially common in formal writing.

Because حارس المرمى is an iḍāfa construction, often called a genitive construction.

In an iḍāfa:

• the first noun usually does not take الـ
• the whole phrase can still be definite if the second noun is definite

So:

• حارس = keeper / guard
• المرمى = the goal

Together:

• حارس المرمى = the goalkeeper
• literally: keeper of the goal

So even without الـ on حارس, the whole phrase is definite because المرمى is definite.

It is an iḍāfa:

• حارس = the first term
• المرمى = the second term

The relationship is like X of Y:

• حارس المرمى = keeper of the goal

A few useful things happen in iḍāfa:

• the first noun does not take الـ
• the second noun is in the genitive
• the whole phrase can be definite

So this is a very common Arabic way to say things like:

• باب البيت = the door of the house
• مدير المدرسة = the principal of the school
• حارس المرمى = the goalkeeper

Because the final ى here is alif maqṣūra, which is pronounced like a long ā sound.

So:

• المرمى = al-marmā

Even though it looks a little like yāʾ, in this word it does not sound like y.

This word is also the second part of the iḍāfa, so it is grammatically genitive, but that case ending is not obvious here because words ending in ى behave a bit differently.

Because it is not part of the noun phrase حارس المرمى. It is describing the state the goalkeeper seems to be in.

So the structure is roughly:

• يبدو = seems
• حارس المرمى = the goalkeeper
• جاهزًا = ready

If جاهز were an ordinary adjective directly attached to the noun, it would normally match it in definiteness. But here it works more like the description after seems in English:

• The goalkeeper seems ready

not:

• the ready goalkeeper

That is why جاهزًا is indefinite.

In the fully vocalized sentence, it is:

يبدو حارسُ المرمى جاهزًا

Here:

• حارسُ is nominative because it is the subject
• جاهزًا is accusative because it describes the state in which the subject appears

This kind of word after يبدو is often analyzed as a ḥāl (circumstantial accusative), meaning it describes the condition of the subject.

So in simple learner terms:

• حارسُ المرمى = the subject
• جاهزًا = the state he seems to be in

The fully vowelled sentence is:

يبدو حارسُ المرمى جاهزًا

Breakdown:

• يبدو = verb
• حارسُ = subject, so nominative
• المرمى = second term of iḍāfa, so genitive
• جاهزًا = accusative state word

In normal unvowelled writing, these endings are usually not shown, which is why you see:

يبدو حارس المرمى جاهزا

In careful MSA pronunciation, it is approximately:

yabdū ḥārisu al-marmā jāhizan

A few key points:

• يبدو = yabdū
• ح in حارس is a stronger h sound
• المرمى ends in a long ā
• جاهزًا is jāhizan in full reading

In less formal speech, learners will often hear reduced case endings, but the careful MSA form above is the useful one to know.

Yes. A very common alternative is:

يبدو أن حارس المرمى جاهز

That also means It seems that the goalkeeper is ready.

The difference is mainly structural:

• يبدو حارس المرمى جاهزًا = more compact
• يبدو أن حارس المرمى جاهز = uses a full clause after يبدو

Both are good Arabic, and learners will see both patterns often.